Motor operator for load break switch



Nov. 4, 1969 H. L. GERARD 3,475,981

MOTOR OPERATOR FOR LOAD BREAK SWITCH Filed Nov. 20. 1967 2 Sheets-Sheet1 HOWARD L. 65/84/20 INVENTOR. F .1. .l M 7 5 MW 4 TTORNEVS' Nov. 4,1969 H. L. GERARD 3,475,981

MOTOR OPERATOR FOR LOAD BREAK SWITCH Filed Nov. 20. 196'? 2 Sheets-Sheet2 INVENTOR. 4 HOWARD L GERARD BY M United States Patent 3,475,981 MOTOROPERATOR FOR LOAD BREAK SWITCH Howard L. Gerard, Houston, Tex., assignorto Powell Electric Manufacturing Co., Houston, Tex. Filed Nov. 20, 1967,Ser. No. 684,252 Int. Cl. F16h 27/02 U.S. Cl. 74-143 6 Claims ABSTRACTOF THE DISCLOSURE This application discloses a motor operator for a loadbreak switch that is opened and closed by rotation of an operating shaftin opposite directions. The operator includes first and second ratchetwheels, which are mounted on the operating shaft of the switch forrotation with the shaft with their ratchet teeth facing in oppositedirections. First and second ratchet members are positioned to engagethe first and second ratchet wheels respectively to rotate them inopposite directions. Each ratchet member has one end rotatably mountedon an eccentric to be reciprocated by rotation of the eccentric. Theeccentric is driven by a motor. A shifting lever controls which of thetwo ratchet members are in engagement with its associated ratchet wheelat any given time, which determines the direction the operating shaft irotated. The shifting lever is movable between a first position with thefirst ratchet member in engagement with the first ratchet wheel torotate the wheel and the operating shaft of the switch in one direction,when the ratchet member is reciprocated by the eccentric, and a secondposition with the second ratchet member in engagement with the secondratchet wheel to rotate the wheel and the operating shaft of the switchin the opposite direction, when the second ratchet member isreciprocated by the eccentric. The shifting lever is moved between thetwo positions in response to movement of the switch between its open andclosed positions so that the ratchet member that is in engagement withits associated ratchet wheel will be rotating the shaft to change theswitch from the condition that it i in at that time, regardless of thedirection of rotation of the eccentric.

This invention relates to a motor operator for a load break switch.

Most load break switches are operated by an operating shaft that isrotated in opposite directions to move the switch contacts between theiropened and closed positions. Heretofore, motor operators for theseswitches required some means of changing the direction of output powersupplied to the operating shaft. This was accomplished usually byreversing the direction of rotation of the motor, which required closecontrol to keep the motor from continuing to supply power to theoperating shaft after the position of the switch was changed.

Also, preferably, load break switches are both manually or motoroperated. Motor operation allow the switch to be remotely controlled,whereas manual operation is convenient when working on the switch ortesting it. Also, the ability to operate this type of switch manually isimportant for safety purposes should the motor operator fail for somereason. In the previously used motor operators, a clutch was used todisconnect the operating shaft from the driving motor to permit manualoperation. This further complicated the operation of the operator.

It is an object of this invention to provide an improved motor operatorfor a load break switch that does not interfere with the manualoperation of the switch thereby allowing the switch to be operatedmanually without having to disconnect the motor operator from theoperating shaft of the switch.

3,475,981 Patented Nov. 4, 1969 It is yet another object of thisinvention to provide a motor operator for a load break switch that willdrive the operating shaft of the switch in the direction required tochange the position of the switch contacts even though the motor drivingthe operator continues to operate in the same direction.

It is another object of this invention to provide a motor operator for aload break switch that allows the motor driving the operator to rotatein the same direction while rotating the operating shaft of the switchin opposite directions to open and close the switch.

It is a further object of this invention to provide a motor operator fora load break switch of the type that stores energy in a spring fortriggering the movement of the contacts from either the opened or theclosed position that will hold whatever energy is stored in the springby the motor when the motor is shut down without transmitting thisenergy back to the drive shaft of the motor.

These and other objects, advantages, and features of this invention areobtained by ratchet assemblies arranged as follows: Two ratchet wheelsare mounted on the operating shaft of the load break switch with theirratchet teeth facing in opposite directions. A ratchet member isassociated with each ratchet wheel for driving it in the directionopposite from the direction the other ratchet wheel is driven. Aswitching lever is arranged to move one or the other of the ratchetmembers into engagement with its associated ratchet wheel in response tothe position of the contacts of the switch. Thus, when the switch isopen, the switching lever will be in position to hold the ratchet memberin engagement with the ratchet wheel that will rotate the operatingshaft in the direction required to close the switch. Conversely, whenthe switch is closed, the switching lever moves the other ratchet memberinto engagement with its associated ratchet wheel to drive the operatingshafts in the opposite direction to open the switch. The ratchet memberscan be reciprocated in any convenient manner. In the preferredembodiment, they are reciprocated by an eccentric driven from the outputshaft of a motor. This allows the motor operator to operate the switchand rotate the operating shaft in different directions although theoutput shaft of the motor rotates in the same direction at all times.Further, the switch can be operated manually at any time and the ratchetmember in engagement with its associated ratchet wheel at that time willsimply ratchet and not interfere in any way with further rotation of theratchet wheel.

The invention will now be described in detail in connection with theattached drawings in which,

FIGURE 1 is a front View of the preferred embodiment of the motoroperator in position to rotate the operating shaft of a load breakswitch in a clockwise direction;

FIGURE 2 is a view similar to FIGURE 1 with the operator in position todrive the omrating shaft of the switch in the opposite direction fromthat in which it is driving it in FIGURE 1; and

FIGURE 3 is a perspective view of a portion of the operating mechanismof a load break switch.

It is very important that load break switches be opened and closedrapidly. This is done usually by storing energy, such as spring energy,and then releasing this energy rapidly to open or close the switchcontacts. FIGURE 3 illustrates the arrangement used on General Electricload break switch, model SE-100, one of such switches upon which themotor operator of this invention has been used.

Operating shaft It) is arranged to rotate shaft 9 (FIG- URE 3) uponwhich is mounted two arms, only one of which, arm 8, is shown. As arm 8is rotated with shaft 9, it moves away from stop 5 and compresses spring7 until the arm passes a position in line with the longitudinal axis ofthe spring. Movement of arm 8 past this position releases the energystored in spring 7, and a similar spring 7a compressed by the other armmounted on the shaft, which quickly rotates arm 8 and shaft 9 to aposition against stop 6, 180 from its previous position. A lost motionconnection between shaft 9 and the switch contacts allow arm 8 to bemoved to its in-line position with spring 7 without moving the movablecontacts of the switch. As the springs take over, however, shaft 9 willmove the contacts into or out of engagement with the stationary contactsof the switch depending on the direction of movement of shaft 9.

Thus, rotation of operating shaft 10 in one direction opens the contactsof the switch. Rotation in the other direction closes them. It is notimportant for our purposes here which direction does what. For manualoperation of the switch, operating shaft 10 is provided with centralopening 11 and laterally extending slots 12 and 13 to receive a crank ofconventional design.

The motor operator of this invention includes first ratchet wheel 14 andsecond ratchet wheel 15. These ratchet wheels are mounted side by sideon operating shaft 10 and held against rotation relative to the shaft bykey 16. The two wheels are connected together by machine screws 17.

The ratchet wheels are mounted on shaft 10 with their ratchet teethfacing in opposite directions. The teeth on first ratchet Wheel 14 arearranged to rotate the shaft in a clockwise direction, whereas the teethon second ratchet wheel 15 are facing in the direction to rotate theshaft in a counterclockwise direction. To rotate the ratchet wheels,first ratchet member 18 and second ratchet member 19 are provided forengaging the first and second ratchet wheels, respectively. In theembodiment shown, the ratchet members are elongated members ofrectangular cross-section. The ends of the members that engage theratchet wheels are shaped, as shown, to provide pointed edges 18a and19a to engage the teeth on the periphery of the Wheels.

Means are provided for reciprocating the ratchet members to cause eachmember to move the ratchet wheel it engages. In the embodiment shown,each ratchet member has one end rotatably mounted on eccentric 20. Thecccentric comprises a cylindrical member mounted on output shaft 21a ofelectric motor 21 with its longitudinal axis parallel to but offset fromthe axis of shaft 21a. Thus, this will cause eccentric 20 to reciprocateratchet members 18 and 19 as it is rotated by shaft 21a.

Means are provided, which are responsive to the position of the switch,to move one of the first and second ratchet members into engagement withits associated ratchet wheel and for moving the other ratchet member outof engagement with its associated ratchet wheel to cause the operatingshaft of the switch to be rotated in the direction required to changethe position of the switch, when the ratchet members are reciprocated.Ratchet members 18 and 19 extend upwardly from eccentric 26 on oppositesides of ratchet wheels 14 and 15 and are connected together, as by weld23, to fix the an le between them.

Shifting lever 22 is rotatably mounted on output shaft 21a of electricmotor 20. Carried by shifting lever 22 and located on opposite sides ofthe ratchet members are first and second resilient stop assemblies 24and 25.

Stop assemblies 24 and 25 include rectangular blocks 26a and 27a, whichare attached to positioning arms 26 and 27 (FIGURE 4). The positioningarms are fixed to shifting lever 22 by bolts 28 and 29, which can heloosened to allow the position of blocks 26a and 27a to be adjusted.Block 26 has concentric openings 30 and 31 of different diameters.Spring 32 is located in opening 30 and exerts a resilient force on pin33, which extends through opening 31 to engage the side of ratchetmember 18. The end portion of pin 33 located in opening 38 is enlargedto about the diameter of the opening for engagement by spring 32. Setscrew 34 allows the force exerted by spring 32 on pin 33 to be adjusted.In the same manner, spring 32, set screw 35, and pin 36 are arranged inopenings 37 and 38 in block 27a so pin 36 will engage the side ofratchet member 19.

The first and second resilient stop assemblies 24 and 25, respectively,are positioned on shifting lever 22 so that when the lever is in theposition shown in FIGURE 1, first stop assembly 25 will resiliently holdfirst ratchet member 18 in position to engage the teeth on first ratchetwheel 14 to move the operating shaft 10 in a clockwise direction as theratchet member is reciprocated by eccentric 20. Moving ratchet arm 18into engagement with its ratchet wheel will move ratchet arm 19 out ofengagement with ratchet wheel 15, since the angle between them is fixed.

By moving shifting lever 22 to the position shown in FIGURE 2, itssecond position, the second stop assembly 25 will move up so that pin 36moves ratchet member 19 into engagement with ratchet Wheel 15. Then asratchet member 19 is reciprocated, ratchet wheel 15 will rotate theoperating shaft of the switch in a counterclockwise direction. As theshifting lever is moved to its second position, first stop assembly 24will move far enough to the left, as viewed in FIGURES 1 and 2 to permitratchet member 18 to be moved out of engagement with the first ratchetwheel 14 by the movement of member 19.

Shifting lever 22 is moved between its first and second positions byactuating arm 40 and link 41, which is connected to the actuating arm bypin 42. Link 41 moves only when the switch contacts move. Thus, when theswitch moves to the open position, link 41 will cause the shifting leverto be moved quickly from its first to its second position by the samespring energy used to move the switch contacts. This can be accomplishedin various ways, as, for example, by arranging link 41 to be moved byshaft 9 (FIGURE 3) through a lost motion connection. Therefore, therewill be no gradual movement of shifting lever 22 from one position tothe other as the operating shaft is rotated, but link 41 will operateonly as the spring energy is released which, at that time, will placethe switch in position for the operating shaft to be rotated in theopposite direction. Therefore, the ratchet members will be in positionto continuously rotate operating shaft 10 in the proper direction, i.e.,in the direction to change the condition of the switch, even though themotor driving the operator runs continuously in the same direction.

Pawls 44 and 45 are rotatably mounted on pin 46 and located below theratchet wheels and between the ratchet members. Pin 46 is supported byplate 55. Like ratchet members 18 and 19, pawls 44 and 45 are connectedtogether, as by Weld 56, to fix the angle between them. The pawls arearranged to hold the ratchet wheels from rotating in a directionopposite that from which they are being rotated by the actuatingmembers. This is necessary to allow energy to be stored in the actuatingsprings of the switch. For example, if first ratchet member 18 isrotating first ratchet wheel 14 and building up energy in switch spring7 to operate the switch, if ratchet wheel 14 were not held againstrotation in a counterclockwise direction each time ratchet member 18moves back to engage another tooth, the spring would simply force theratchet wheel to move in a counterclockwise direction and the wheelwould simply set there and oscillate with the reciprocation of ratchetmember 18. Therefore, as ratchet member 18 moves into engagement withratchet wheel 14, as shown in FIGURE 1, spring loaded pin 47 engagesfirst pawl 44 and moves it into position to engage the teeth on ratchetwheel 14. Pin 47 is resiliently held in engagement with pawl 44 byspring 48. The pin extends through opening 49 of relatively smalldiameter, whereas spring 48 is located in bore 50 of increased diameter.Set screw 51 allows the spring force on pin 47 to be adjusted.

In the same manner, pin 52 engages second pawl 45 and moves it intoposition to engage the teeth on second ratchet wheel 15, when shiftinglever 22 is moved to the position shown in FIGURE 2. Pin 52 isresiliently held in engagement with pawl 45 by springs 53. The anglebetween the pawls is such that the movement of one pawl into engagementwith a ratchet wheel will move the other out of engagement with itsassociated ratchet wheel.

Pins 33, 36, 47, and 52 are held in engagement with the various membersof the operator by springs so that the pawls and ratchet members canmove outwardly far enough to ride over the teeth on the ratchet wheels,as this is required in the operation of the mechanism.

From the foregoing, it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forth,together with other advantages which are obvious and which are inherentto the apparatus and structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, itis to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. A motor operatorfor a load break switch that is opened and closed by rotation of anoperating shaft in opposite directions, comprising first and secondtoothed ratchet wheels mounted on the operating shaft of the switch forrotating with the shaft with the teeth on the wheels facing in oppositedirections; first and second ratchet members, means mounting the firstratchet member for movement into and out of driving engagement with thefirst ratchet wheel to move the ratchet wheel in one direction, when thefirst ratchet member is reciprocated, means mounting the second ratchetmember for movement into and out of driving engagement with the secondratchet wheel for moving the second ratchet wheel in a directionopposite to the direction the first wheel is driven, when the secondratchet member is reciprocated, means responsive to the position of theswitch for moving one of the first and second ratchet members intoengagement with its associated ratchet wheel and for moving the otherratchet member out of engagement with its associated ratchet wheel tocause the shaft to be rotated in the direction required to change theposition of the switch when the ratchet members are reciprocated, andmeans for reciprocating the ratchet members.

2. The motor operator of claim 1 in which the means for reciprocatingthe ratchet members includes an eccentric upon which both ratchetmembers are rotatably mounted and means for rotating the eccentric tocause the members to reciprocate.

3. The motor operator of claim 2 in which the eccentric and the ratchetmembers are positioned with the ratchet members extending from theeccentric on opposite sides of the ratchet wheels.

4. The motor operator of claim 3 in which the means for moving one ofthe ratchet members into, and the other out of, engagement with theratchet wheels, respectively, includes a shifting lever rotatablymounted intermediate its ends on the eccentric; first and secondresilient stop assemblies carried by and fixed relative to the lever andlocated on opposite sides of the ratchet members to engage the first andsecond ratchet members, respectively, and means for rotating theshifting lever between a first position with the first stop assemblyholding the first ratchet member in engagement with the first ratchetwheel to rotate the wheel and the operating shaft of the switch in onedirection when the ratchet member is reciprocated by the eccentric and asecond position with the second stop assembly holding the second ratchetmember in engagement with the second ratchet wheel to rotate the wheeland the operating shaft of the switch in the opposite direction when thesecond ratchet member is reciprocated by the eccentric.

5. The motor operator of claim 4 further provided with first and secondpawls for alternately engaging the first and second ratchet wheels,respectively, to hold the ratchet wheels from rotating in a directionopposite from the direction each is rotated by its ratchet member.

6. The motor operator of claim 5 in which the pawls are pivotallymounted between the ratchet members and the ratchet wheels and in whichthe first and second ratchet members carry first and second resilientpawl actuating assemblies for engaging the first and second pawls,respectively, to hold the first pawl in position to hold the firstratchet wheel from rotating in a direction opposite the direction thefirst ratchet wheel is rotated by the first ratchet member when it isheld in engagement with the first wheel by the first stop assembly andreciprocated and to hold the second pawl in position to hold the secondratchet wheel from rotating in a direction opposite the direction thesecond ratchet wheel is rotated by the second ratchet member when it isheld in engagement with the second wheel by the second stop assembly andreciprocated.

References Cited UNITED STATES PATENTS 47,315 4/ 1865 McGill 74-1432,401,801 6/1946 Seese 335-73 FOREIGN PATENTS 613,234 11/1948 GreatBritain.

FRED C. MATTERN, 111., Primary Examiner W. S. RATLIFF, JR., AssistantExaminer

